Flexible bags are frequently used to line tanks and other rigid containers to hold various types of liquids and flowable solids. Such bag liners are advantageous because they reduce or eliminate clean up of the tanks, enable highly caustic, acidic, or other chemically reactive or hazardous materials to be stored without damaging the tank, and are relatively cost effective. However, if a fluid tight seal between the outlet spout of the flexible bag liner and the tank discharge outlet is not achieved and maintained, liquid within the liner can flow around the spout and between the liner and back into the tank increasing clean up and possibly damaging the tank. Likewise, if the spout is not adequately secured within the tank outlet, the bag can float to the top of the tank as liquid is drained, pulling the spout out of the outlet and causing the contents of the bag to leak into the tank.
Unfortunately, a spout providing a fluid-tight seal and anchoring the bag within the container requires a great deal of force to both insert the spout into the discharge outlet before filling the bag and to remove the spout after emptying the bag. Entry into the container to manually engage the spout is generally impractical since it may be unsafe or difficult to maneuver within the tank, cause damage to the liner resulting in contamination of the tank, or require more force than physically available to insert or remove the spout. Similarly, a person attempting to manually insert or remove the spout from outside the tank is not likely to possess a sufficient mechanical advantage to apply an adequate amount of force to complete the task. Moreover, unless the force is applied generally along the axis of the spout, the seal may not be fluid-tight or may fail to anchor the liner when seated, removal or insertion of the spout may be more difficult, or the spout may be damaged resulting in contamination of the tank.